multiétages

CONT: Conventional space launchers are ""multi-stage"": that is, the launcher is not a single rocket but is actually a ""stack"" of two or three rockets or ""stages"" that contain their own propellants and have their own engines. The first stage lifts the vehicle from the ground and accelerates it for the first part of its ascent. When its propellants are all consumed, the first stage is discarded (jettisoned) and the next stage fires to accelerate the vehicle further. The second stage is discarded when it, too, is spent in a three staged vehicle. Additional boosters are sometimes ""strapped on"" to the vehicle to supplement the main engines, and these are also jettisoned when exhausted.
PHR: Multi-stage space launch vehicle.